Currently, numerous third-party applications may be used in social networking systems. These third-party applications include, for example, multi-player games (e.g., Farmville™, Cityville™ and Words with Friends™), applications linked to the user's blogs (e.g., Wordpress™) as well as applications related to other social networking websites (e.g., Pinterest™, Yelp™, Spotify™ and Turntable.fm™).
The challenge for the social networking systems that act as intermediaries between the user and the third-party applications is to ensure that important information from these applications be received by the user while preventing the user from being spammed or overloaded with unwanted communications.